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In the traditional specification of interference fits, loads on the joint such as the torque and axial force are taken into account. However, radial and cantilever loads must also be considered. As an example, the fit of a conical gear on a shaft with complex loading is analyzed.

The use of the following quality-control instruments in the machining of cylindrical liners at repair shops is considered: Shewhart charts (of moving-range and individual-measurement types) and histograms for analysis of the adjustment precision. A monitoring checklist has been developed for determining the losses due to all defect types. Interchangeability among groups for piston–liner assemblies completely eliminates wasted inventory.

The application of classical quality control tools in the processing of cylinder liners for repair size is considered: Shewhart cards of sliding ranges and individual values, as well as histograms for analyzing the accuracy of the technological process control. A checklist has been developed to identify waste and losses for all types of defects. The method of intergroup interchangeability for the pistonsleeve joint, which completely eliminates inventory backup, is substantiated and implemented. Keywords control, quality, control tool, cylinder liner, selective assembly. metr@rgau-msha.ru

The theoretical substantiation of the method of relative interchangeability in cylindrical joints with preload is given. Examples of connection of shafts with a repairable defect and parts with holes with an irrepairable defect and on the contrary at maintaining of required accuracy of joint on limiting preload are given. Keywords interchangeability, tolerance, size, fit, preload, repairable and irrepairable defect metr@rgau-msha.ru

The article deals with the issues of typification of elements of irrigation systems in land reclamation. When designing irrigation systems it is necessary to take into account measures for the agricultural development of reclaimed lands. The natural and economic conditions of the irrigation area, the characteristics of the irrigation source, the irrigation area and its configuration affect the composition of the irrigation system elements, their location, network design, and in each specific case change the irrigation system. Typical technological elements of irrigation systems allow to design quickly the system taking into account the features. In this regard, a nomenclature of typical technological elements of irrigation systems was proposed, consisting of 6 modules. An analysis of the range of controlled parameters on each module in the design and calculation version was also carried out.

The article has devoted to solving an urgent problem related to the analysis of the quality of manufacturing sprockets for chain drives of agricultural machinery. For the conditions of a technical service enterprise specializing in the maintenance and repair of agricultural machines, an experimental assessment and analysis of the quality of spare parts - sprockets, which have a fit on the shaft of the H090 gearbox of the Mosselmash plant. It had revealed that the factory set the requirements for the inner diameter of the sprocket Ø30H7(+0.021). Measurements of the hole of 100 stars had carried out, as a result of the analysis of the experimental data obtained, the following had established: scattering parameters and quality parameters for manufacturing controlled dimensions. Using empirical data, a histogram and a theoretical curve for the distribution of the internal diameters of the sprocket had constructed. It had revealed that the probability of the appearance of suitable parts is 83%, parts with a correctable defect − 8%, with an unrecoverable one − 9%. On the basis of the obtained data, in order to improve the quality of manufacturing chain sprockets, appropriate recommendations had made to the manufacturer.

Issues related to the evaluation of the results of direct multiple measurements with a worn digital micrometer have considered. It had determined that the total error of the device used in operation exceeds the limit of permissible error indicated in the passport by 1.25 times and is equal to 5 μm. But in the field of control of parts in repair production, the passage of mandatory verification by measuring instruments is not required, and the calibration operation is advisory in nature. Based on the obtained value, we can conclude that the device can be used to measure the dimensions of parts with a tolerance of at least 15 µm.

A formula for the theoretical tolerance in fitting is derived by analysis of the components in the model of parametric failure for joints with interference. The formula takes account of the life of the joint and the specified probability of fault-free operation. It is found that selection of the fit without a margin of precision does not ensure the necessary reliability of the joint, while correct selection of the margin of precision extends the fault-free operation of the joint.

The article discusses the issues of ranking the assortment of Russian-made cognac using ABC analysis. ABC analysis allows you to select the most significant objects from the whole set of the same type, that is, to select objects that are few, but which need to be paid close attention to. To rank the cognac assortment, an ABC analysis was conducted, which showed that Group A cognacs are in the greatest demand, bring the greatest profit, so they should always be in stock. The second group includes cognacs that are in stable demand among consumers, which also indicates good sales and profits. The presence of Group B cognacs is also important for the company, but cognacs of this group can be modeled at a calmer and moderate pace. Group C - has the lowest demand from consumers. The reason is the high price of goods of this group, since not every consumer can afford to buy high-quality cognac. To improve the assortment and improve the quality of brandies sold by companies, it was proposed to expand the range of cognacs by introducing new names and types, which will help attract new consumers; take into account factors affecting the development and formation of the range of cognacs.

Currently, the ordering of standardization objects and their properties, optimization of the parameters of standardization objects, normalization of requirements for objects are the most important areas of standardization as a science. In this regard, the issues of choosing parametric series are very relevant. In order to increase the level of interchangeability and reduce the range of products and standard sizes of blanks, overall cutting tools, tooling, productivity, speed, speed, power, etc., used in a particular industry, as well as to create conditions for effective specialization and cooperation of plants, reduce the cost of products, the principle of preference is used in the unification and development of standards. There are two methods for choosing parametric series: the method of technical justification and the method of economic justification. The technical method is easier to use and is used to expand the technologies of unification of standard sizes of parts of homogeneous products. This method was used to calculate a number of diameters of hydraulic cylinders of broaching machines of the same series based on the mathematical dependence between the force developed on the hydraulic cylinder rod, which is formed by the initial parametric series laid down by the designers. As a result of technical optimization of the choice of the parametric series, a number of diameters of hydraulic cylinders R20/2(45-224) mm was installed, fully corresponding to the main functional parameter - a number of forces on the rod of broaching machines R10/2(0.63-16.0) kN.

The article deals with the mechanism of quality control of agro-industrial production processes, namely, quality control of poultry farm processes. It also details the management of nonconforming products using simple quality control and management tools – a checklist and a Pareto chart. It was suggested that a checklist should be used to record nonconformities and their number for each nonconformity. Using this checklist form will allow you to analyze the production process, identify the causes of nonconformities, and quickly intervene in the process to prevent nonconformities from occurring. To analyze the inconsistencies and the causes of their occurrence, it was suggested to use the Pareto diagram, the use of which allows you to pay attention to the most significant problems.

This article contains substantiation of the improvement of inspection instruments used for the repairs of farming machinery during incoming quality inspection, in-process inspection, and acceptance testing. The design of a gauge plug has been developed for repairs and with the purpose of inspection of bushing bores of the intermediary shaft bearing with the diameter of Ø48.8F7 for ZMZ engines. The manufacturing tolerance for go-side and no-go side has been determined. The deviation of the middle of the tolerance range in relation to the smallest limiting size of the gauge plug was 3.5 μm. The permissible overrun of a worn-out of the gogauge outside of the tolerance range border was – 3 μm. The manufacturing tolerance for the size of the check caliper gauge has also been determined and limiting dimensions of the check gauge have been calculated. Taking into account the values derived a layout for the gauge plug tolerance range has been developed in order to inspect the bushing bores of the intermediary shaft bearing with the diameter of Ø48,8+0,050 +0,0025.

The article has devoted to a topical topic, includes the modeling of technological processes for the cultivation of crop products. As an object of research, the process of cultivation of fodder lupine had chosen. The analysis of the process of cultivation of crop products from the point of view of the Deming cycle has carried out. The production of feed lupine has presented as a system of interrelated processes. A passport of the process «Production of fodder lupine» has been developed, which contains brief information about the projected process: inputs, outputs, resources, control mechanisms, etc. The top-level model «Production of fodder lupine» in IDF0 notation has developed. The developed model can be used as the basis for building a quality management system for lupine cultivation. The proposed approach will allow to achieve the quality of the crop and achieve the set goals.

Distortion of the shape of the component parts leads to a decrease in the operational properties of these parts Thus, in movable joints the deviation of the component parts from the correct cylindrical shape leads to an inadequacy of its movements, rapid wear due to contact over a limited surface. In fixed joints, distortion of the shape leads to uneven tension in the joints, because of this, the strength of the joint, the tightness and the accuracy of the centering decrease. Distortion form also affects labor and assembly accuracy, increases the amount of trimming work affects the accuracy of basing of parts in the manufacture and control. Deviations in the location of surfaces from their nominal values are extremely detrimental to the reliability of the machines, causing additional static and dynamic loads in separate parts and joints, which leads to rapid wear and fatigue failure of the parts. Tolerances location or shape to be set for shafts or openings may be independent and dependent. Dependent location tolerances are set for the items, which are interfaced with the object at the same time on two or more surfaces, and for which the interchangeability requirements are reduced to ensure the collection, ie, connectivity details on all mating surfaces. Dependent tolerance indicated in the drawing or other technical documents value which may be greater than the value of which depends on the deviation of the actual size of the element and / or the base material of the maximum limit. On the example of the shaft of the unified reducer of the MOSSELMASH plant, under the designation H090.040, three variants of the assignment of the dependent tolerance of alignment are considered, which, on the one hand, allows to expand the capabilities of the technological equipment and reduce the cost of processing, and on the other hand, ensure the assembly of connections without fitting. For our example, the use of the third variant of the notation extends the alignment tolerance of the two shaft surfaces from 0.010 to 0.048 mm, which is not only economically feasible, but also allows the use of full interchangeability to be competently used.

The urgency of research on the issues of substantiating the requirements for the accuracy of measurements of linear dimensions has substantiated. The main differences between the means for measuring external and internal dimensions have formulated. The factors influencing the choice of measuring instruments have considered. Specific additional measurement errors associated with the alignment of the measurement line with the hole diameter have described. A comparative analysis of the possibility of using various types of bore gauge to control the internal dimensions of holes during machine repair has carried out. The results of an experimental evaluation of the components of the measurement error of a two-point bore gauge have presented. The criterion for the selection of measuring instruments for measuring the holes of objects of maintenance of machinery and equipment has been substantiated. Recommendations have given aimed at improving the accuracy of measuring the holes of parts during the repair of machinery and equipment.

The foundations of the modern approach to quality management at enterprises also include elements of metrological support, which gives a certain effect from control. Universal measuring instruments for linear quantities are widely used in single and small-scale production, as well as in the repair of machines, it is with them that engineers first get acquainted when conducting laboratory measurements. Versatile measuring instruments also include a lever micrometer that can be used for absolute and relative measurements. The article discusses the issues of improving the method of relative measurements of deviations using a lever micrometer with deviations outside the measurement range of the reader, and provided that the tolerance does not go beyond the measurement. Using the technique of relative measurements with a lever micrometer will allow you to quickly perform a large number of measurements in a short time with the required accuracy.

The technique and features of micrometering of cylinder liners are presented. The main factors influencing the wear of the cylinder liner and the rules for assigning planes and sections when conducting a micrometer of its inner surface are theoretically substantiated. On the example of a study of used cylinder liners of engines of the Yaroslavl Motor Plant, it was revealed that the greatest wear is manifested in the place where the upper piston ring stops in the upper part of the liner, and the amount of wear will be greater in the swinging plane of the connecting rod due to the action of normal force during pressure distribution at the beginning of the expansion stroke. High wear at the top is also due to high temperatures and lack of lubrication. It was found that the diameter of the upper non-wearing band can be used to judge the initial size of the sleeve hole. The underside of the cylinder liner is subject to wear due to the friction of the piston skirt against its surface.

The article presents a mechanism for analyzing the costs of the process from the point of view of assessing the effectiveness of the functioning of the quality management system at mechanical engineering enterprises of repair profile. The analysis of the costs of the process can be carried out in four directions: analysis of the effectiveness and efficiency of the process, analysis by type of costs, analysis of the effectiveness of measures to improve the process, comparison of the amount of costs for compliance and losses from non-compliance with the main economic indicators of the economic activity of the enterprise. Each direction can be applied independently, but in order to achieve reliable results and optimize the cost of quality, it is necessary to analyze the cost of quality in the four proposed directions. We analyzed the costs of repairing KAMAZ engines in four directions and came to the following conclusion: the introduction of a process cost management system allows us to timely identify process inconsistencies and take measures to eliminate them and reduce the risk of occurrence in the future, it is necessary to increase the amount of preventive costs in order to shift the break-even point right, it is necessary to take measures that actually prevent the occurrence of possible problems, the costs of compliance and losses from inconsistencies in sales are significant, therefore, measures should be taken to identify, analyze and assess the risk of inconsistencies in production and corrective actions to reduce the share of costs in total sales volume.

The unified system of tolerances and fits is a very important system that provides internationally the interchangeability of products, and is widely used in machine-building and instrument-making industries, in repair and maintenance of machinery and in other fields. The new standard 286-1:2010 of International Organization for Standardization provides an improved international system of tolerances on linear dimensions containing series of tolerances and deviations. It contains the clear indication that the system refers to the two types of dimensional features, namely a cylinder and two parallel planes. In the older version of the standard 286-1:88, to interpret the part feature dimension the rule of outer limits was applied a priori, however, in the international standard 14405-1:2010, the interpretation of dimension on the double-point measurement was established. It means that the accuracy of form deviation no longer depends on the dimension accuracy and the requirements to the form should be established separately. Now, in many cases, normalization only of the diameter tolerance is not enough to control the design and performance characteristics of the joint. Theoretically, as provided by geometrical product specifications, it is necessary to establish the requirements and determine the outer limit; as well as in some cases, it is necessary to normalize the requirements for tolerances of form, waviness and surface roughness. The article describes the changes in the terminology from the perspective of the theory of precision and interchangeability. It is concluded that all minor changes in the terms, concepts and regulations do not affect the overall construction of the unified system of tolerances and fits, but clarification of a number of old terms and introduction of new concepts take place. Most significant is the arising of new link between the standards on geometric characteristics of products based on the principle of the general construction of models of precision and common terminology. Of particular note is a bad translation of English version into Russian language. The scientists working in the theory of precision and interchangeability were not involved in the translation. Most of the newly introduced terms could be interpreted more technically-oriented and more understandable.

Features of quality assurance of production at machine-building enterprises of repair profile are considered. It is revealed that a large number of methods and means of restoring worn parts are used in the repair of machines − mechanical processing, surfacing and welding, metallization and spraying, electrolytic build-up, plastic deformation, and many others. A critical description of the existing theoretical positions on the choice of the most appropriate ways to restore details is presented. It is revealed that the existing methods are based on the criteria of manufacturability, durability and economy and consider the problem of whether it is appropriate to choose a particular method of restoration for only one part forming a joint. A model has been developed to optimize the cost of repairing parts that form a joint, taking into account both the cost of restoring each part and the cost of processing them. Calculations are made for a certain probability of failure and a given resource according to the criterion of the lowest total costs.

The article considers the factors influencing on the quality of manufacture and repair of agricultural machinery from the perspective of application of one of the newest methods of the quality analysis known as Principle of 5 M - men, methods, materials, machines, measures. It is defined that in all five indices the domestic agricultural machinery considerably lags behind the foreign one. The main reasons are the use of cheap raw materials, the lack of modern processing equipment with high precision, the lack of highly skilled and highly paid workers, the designing of machines by means of archaic methods, the small degree of information support on modern technologies and specifics of branch machinery, especially internationally. The role of control in formation of quality of manufacture and repair of agricultural machinery is highlighted. The purchasing manager of a large repair enterprise has to provide in the contract for delivery of incoming production the conditions on the presence of a defined limit of defects with selective check of incoming consignment. For a small enterprise, there is the simple recommendation to take a technical documentation and instruments of control along when going on a warehouse for spares, and to buy only good products of manufacturer or well-established similar products. The main objectives of metrological service in repair enterprises are defined. Modern metrological provision during machine repair is the system ensuring the quality of control that includes: the strict ensuring unity of measurements; the choice of critical control points, which are subject to rigid control; the feasibility study of choice of measuring instruments by criteria of minimization of costs and losses for controlled products; the regular actions on adjustment of measuring instruments, the tests and control during maintenance and repair of agricultural machinery.